<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
	<head>
		<title>Adverbs of Certainty</title>
<link href="../docs-assets/Breadcrumbs.css" rel="stylesheet" rev="stylesheet" type="text/css">
		<meta name="viewport" content="width=device-width initial-scale=1">
		<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
		<meta http-equiv="Content-Language" content="en-gb">

<link href="../docs-assets/Contents.css" rel="stylesheet" rev="stylesheet" type="text/css">
<link href="../docs-assets/Progress.css" rel="stylesheet" rev="stylesheet" type="text/css">
<link href="../docs-assets/Navigation.css" rel="stylesheet" rev="stylesheet" type="text/css">
<link href="../docs-assets/Fonts.css" rel="stylesheet" rev="stylesheet" type="text/css">
<link href="../docs-assets/Base.css" rel="stylesheet" rev="stylesheet" type="text/css">
<script>
function togglePopup(material_id) {
  var popup = document.getElementById(material_id);
  popup.classList.toggle("show");
}
</script>

<link href="../docs-assets/Popups.css" rel="stylesheet" rev="stylesheet" type="text/css">
<link href="../docs-assets/Colours.css" rel="stylesheet" rev="stylesheet" type="text/css">
		
	</head>
	<body class="commentary-font">
		<nav role="navigation">
		<h1><a href="../index.html"><img src="../docs-assets/Inform.png" height=72> </a></h1>
<ul><li><a href="../index.html">home</a></li>
</ul><h2>Compiler</h2><ul>
<li><a href="../structure.html">structure</a></li>
<li><a href="../inbuildn.html">inbuild</a></li>
<li><a href="../inform7n.html">inform7</a></li>
<li><a href="../intern.html">inter</a></li>
<li><a href="../services.html">services</a></li>
<li><a href="../secrets.html">secrets</a></li>
</ul><h2>Other Tools</h2><ul>
<li><a href="../inblorbn.html">inblorb</a></li>
<li><a href="../inform6.html">inform6</a></li>
<li><a href="../inpolicyn.html">inpolicy</a></li>
</ul><h2>Resources</h2><ul>
<li><a href="../extensions.html">extensions</a></li>
<li><a href="../kits.html">kits</a></li>
</ul><h2>Repository</h2><ul>
<li><a href="https://github.com/ganelson/inform"><img src="../docs-assets/github.png" height=0> github</a></li>
</ul><h2>Related Projects</h2><ul>
<li><a href="https://github.com/ganelson/inweb"><img src="../docs-assets/github.png" height=0> inweb</a></li>
<li><a href="https://github.com/ganelson/intest"><img src="../docs-assets/github.png" height=0> intest</a></li>
</ul>
		</nav>
		<main role="main">
		<!-- Weave of 'Adverbs of Certainty' generated by inweb -->
<div class="breadcrumbs">
    <ul class="crumbs"><li><a href="../index.html">Home</a></li><li><a href="../services.html">Services</a></li><li><a href="index.html">linguistics</a></li><li><a href="index.html#3">Chapter 3: VP Categories</a></li><li><b>Adverbs of Certainty</b></li></ul></div>
<p class="purpose">Adverbs such as "usually" or "initially".</p>

<p class="commentary firstcommentary"><a id="SP1" class="paragraph-anchor"></a><b>&#167;1. </b>Inform uses the following scale to measure how certain it is that something
is true:
</p>

<pre class="definitions code-font"><span class="definition-keyword">define</span> <span class="constant-syntax">IMPOSSIBLE_CE</span><span class="plain-syntax"> -2</span>
<span class="definition-keyword">define</span> <span class="constant-syntax">UNLIKELY_CE</span><span class="plain-syntax"> -1</span>
<span class="definition-keyword">define</span> <span class="constant-syntax">UNKNOWN_CE</span><span class="plain-syntax"> </span><span class="constant-syntax">0</span>
<span class="definition-keyword">define</span> <span class="constant-syntax">LIKELY_CE</span><span class="plain-syntax"> </span><span class="constant-syntax">1</span>
<span class="definition-keyword">define</span> <span class="constant-syntax">CERTAIN_CE</span><span class="plain-syntax"> </span><span class="constant-syntax">2</span>
</pre>
<p class="commentary firstcommentary"><a id="SP2" class="paragraph-anchor"></a><b>&#167;2. </b>A special certainty level is used for a temporal sense of certainty:
</p>

<pre class="definitions code-font"><span class="definition-keyword">define</span> <span class="constant-syntax">INITIALLY_CE</span><span class="plain-syntax"> </span><span class="constant-syntax">3</span>
</pre>
<p class="commentary firstcommentary"><a id="SP3" class="paragraph-anchor"></a><b>&#167;3. </b></p>

<pre class="displayed-code all-displayed-code code-font">
<span class="reserved-syntax">void</span><span class="plain-syntax"> </span><span class="function-syntax">Certainty::write</span><button class="popup" onclick="togglePopup('usagePopup1')"><span class="comment-syntax">?</span><span class="popuptext" id="usagePopup1">Usage of <span class="code-font"><span class="function-syntax">Certainty::write</span></span>:<br/>Diagrams - <a href="1-dgr.html#SP3">&#167;3</a></span></button><span class="plain-syntax">(</span><span class="identifier-syntax">OUTPUT_STREAM</span><span class="plain-syntax">, </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">level</span><span class="plain-syntax">) {</span>
<span class="plain-syntax">    </span><span class="reserved-syntax">switch</span><span class="plain-syntax"> (</span><span class="identifier-syntax">level</span><span class="plain-syntax">) {</span>
<span class="plain-syntax">        </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">IMPOSSIBLE_CE:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"impossible"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax">        </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">UNLIKELY_CE:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"unlikely"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax">        </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">UNKNOWN_CE:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"(no certainty level)"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax">        </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">LIKELY_CE:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"likely"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax">        </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">CERTAIN_CE:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"certain"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax">        </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="identifier-syntax">INITIALLY_CE:</span><span class="plain-syntax"> </span><span class="identifier-syntax">WRITE</span><span class="plain-syntax">(</span><span class="string-syntax">"initial"</span><span class="plain-syntax">); </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
<span class="plain-syntax">    }</span>
<span class="plain-syntax">}</span>
</pre>
<p class="commentary firstcommentary"><a id="SP4" class="paragraph-anchor"></a><b>&#167;4. </b>Certainty adverbs are found mainly in regular sentences:
</p>

<blockquote>
    <p>A door is usually open.</p>
</blockquote>

<p class="commentary">They are syntactically legal in existential sentences too, though in English
this usually expresses emphasis rather than a measure of probability: consider
"there certainly are men in the room". Inform allows this, in any case. In
conditions, Inform is more picky. For example, in assertions one can write
</p>

<blockquote>
    <p>A box is usually closed. (1)</p>
</blockquote>

<p class="commentary">but in conditions one can't write
</p>

<blockquote>
    <p>if a box is usually closed, ... (2)</p>
</blockquote>

<p class="commentary">This is because (1) is essentially a statement about the future, not the
present or the past, whereas conditions like (2) must always be determinable at
once: run-time code cannot know what will generally happen, only what is now
the case and what has been the case in the past.
</p>

<pre class="displayed-code all-displayed-code code-font">
<span class="function-syntax">&lt;certainty&gt;</span>
<span class="plain-syntax">    </span><span class="identifier-syntax">always</span><span class="plain-syntax">/</span><span class="identifier-syntax">certainly</span><span class="plain-syntax"> |</span>
<span class="plain-syntax">    </span><span class="identifier-syntax">usually</span><span class="plain-syntax">/</span><span class="identifier-syntax">normally</span><span class="plain-syntax"> |</span>
<span class="plain-syntax">    </span><span class="identifier-syntax">rarely</span><span class="plain-syntax">/</span><span class="identifier-syntax">seldom</span><span class="plain-syntax"> |</span>
<span class="plain-syntax">    </span><span class="identifier-syntax">never</span><span class="plain-syntax"> |</span>
<span class="plain-syntax">    </span><span class="identifier-syntax">initially</span>
</pre>
<nav role="progress"><div class="progresscontainer">
    <ul class="progressbar"><li class="progressprev"><a href="3-prp.html">&#10094;</a></li><li class="progresschapter"><a href="P-wtmd.html">P</a></li><li class="progresschapter"><a href="1-lm.html">1</a></li><li class="progresschapter"><a href="2-adj.html">2</a></li><li class="progresscurrentchapter">3</li><li class="progresssection"><a href="3-vrb.html">vrb</a></li><li class="progresssection"><a href="3-vm.html">vm</a></li><li class="progresssection"><a href="3-sm.html">sm</a></li><li class="progresssection"><a href="3-vu.html">vu</a></li><li class="progresssection"><a href="3-prp.html">prp</a></li><li class="progresscurrent">aoc</li><li class="progresssection"><a href="3-apoo.html">apoo</a></li><li class="progresschapter"><a href="4-np.html">4</a></li><li class="progressnext"><a href="3-apoo.html">&#10095;</a></li></ul></div>
</nav><!-- End of weave -->

		</main>
	</body>
</html>

